Improvement in saws



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117944 PA'mvTEnAUG 81871 V//////////// /ll// s$\\\\\\\ UNITED STATES PATRICK THOMPSON, OF PITTSBUBG, PENNSYLVANIA.

IM PROVEMENT IN SAWS.

Specification forming part of Letters Patent No. 117,944, dated August 8, 1871.

To all whom it may concern:

Be it known that I, PATRICK THOMPSON, of Pittsburg, in the county of Allegheny and State of Pennsylvania, have invented a new and useful Improvement in Saws and I do hereby declare the following to be a full and exact description there of, reference being had to the accompanying drawing and to the letters of reference marked thereon.

The nature of my invention consists in providin g a detached saw-tooth with a tang or dovetail, the ends ofthe tooth being at right angles to avertical line drawn through the body of the tooth, as at line 3 in Fig. 1, so that the line or point of force shall be at the points marked X, whereby the tang G is relieved from the force of the tooth in the process of cutting, and is not thrown upon the tang or weak portion of the tooth.

To enable others skilled in the art to make and use my invention, I will proceed to describe more fully its construction.

In the accompanying drawing which forms part of my specification, Figure 1 is a side view of a section of a saw-blade, in which is secured a tooth by means of a'dovetail or tang. Fig. 2 is a vertical section at line y of Fig. 1.

The saw-blade A is provided with a series of openings equal to the number of teeth desired in the saw. These openings correspond in number, form, and size to the number, form, and size of the teeth B. The form of the teeth and the openings required for them is clearly indicated in Fig.

1. The upper and lower ends of that portion of the teeth marked as are beveled off on .each side so as to form coni-formed ends which fit into V- shaped grooves in the opening for the teeth, as indicated at D in Fig. 2. The dovetail or tang O is bent sidewise, so that the part marked 0 will'pass along the side of the saw-blade until it comes directly over the opening for the part of the dovetail or tang marked 0, which is then forced down into its part of the opening, and thereby secures the tooth securely in the blade of the saw.

The skillful mechanic will readily understand the construction of the teeth, and also the form of the openings required for them, and 110w teeth are inserted and secured in the saw-blade, by reference to the accompanying drawing, without further description.

I wish it clearly understood that I do not claim, broadly, a detached saw-tooth provided with a tang or dovetail for the purpose of securing the tooth in the saw-blade.

What I claim is The saw-tooth B, provided with tang O for securing it in the blade A, constructed as herein shown and described.

PATRICK THOMPSON.

,Witnesses:

A. O. JOHNSTON, JAMES J. JOHNSTON. 

